panic: maddr rwlock 0xffff80000156b860: enter read deadlock Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *452080 84982 0 0x14000 0x40000200 0 softclock db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83325ab2) at panic+0x1cf sys/kern/subr_prf.c:198 rw_do_enter_read(ffff80000156b860,0) at rw_do_enter_read+0x435 sys/kern/kern_rwlock.c:379 in6_hasmulti(fffffd8070f5d2f0,ffff80000156b800) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline] in6_hasmulti(fffffd8070f5d2f0,ffff80000156b800) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150 ip6_output(fffffd8070f5d200,ffffffff839adbf8,0,0,ffff80002a739da0,0) at ip6_output+0x1369 sys/netinet6/ip6_output.c:507 mld6_sendpkt(ffff8000015ae080,83,0) at mld6_sendpkt+0x364 sys/netinet6/mld6.c:499 mld6_fasttimo() at mld6_fasttimo+0x16d mld6_checktimer sys/netinet6/mld6.c:395 [inline] mld6_fasttimo() at mld6_fasttimo+0x16d sys/netinet6/mld6.c:369 pffasttimo(ffffffff838bf828) at pffasttimo+0x184 sys/kern/uipc_domain.c:-1 timeout_run(ffffffff837b82a0,ffffffff838bf828) at timeout_run+0xf3 sys/kern/kern_timeout.c:-1 softclock_thread(ffff80002a72cf90) at softclock_thread+0x12b softclock_thread_run sys/kern/kern_timeout.c:842 [inline] softclock_thread(ffff80002a72cf90) at softclock_thread+0x12b sys/kern/kern_timeout.c:866 end trace frame: 0x0, count: 5 https://www.openbsd.org/ddb.html describes the minimum info required in bug reports. Insufficient info makes it difficult to find and fix bugs. ddb> ddb> set $lines = 0 ddb> set $maxwidth = 0 ddb> show panic *cpu0: maddr rwlock 0xffff80000156b860: enter read deadlock ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83325ab2) at panic+0x1cf sys/kern/subr_prf.c:198 rw_do_enter_read(ffff80000156b860,0) at rw_do_enter_read+0x435 sys/kern/kern_rwlock.c:379 in6_hasmulti(fffffd8070f5d2f0,ffff80000156b800) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline] in6_hasmulti(fffffd8070f5d2f0,ffff80000156b800) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150 ip6_output(fffffd8070f5d200,ffffffff839adbf8,0,0,ffff80002a739da0,0) at ip6_output+0x1369 sys/netinet6/ip6_output.c:507 mld6_sendpkt(ffff8000015ae080,83,0) at mld6_sendpkt+0x364 sys/netinet6/mld6.c:499 mld6_fasttimo() at mld6_fasttimo+0x16d mld6_checktimer sys/netinet6/mld6.c:395 [inline] mld6_fasttimo() at mld6_fasttimo+0x16d sys/netinet6/mld6.c:369 pffasttimo(ffffffff838bf828) at pffasttimo+0x184 sys/kern/uipc_domain.c:-1 timeout_run(ffffffff837b82a0,ffffffff838bf828) at timeout_run+0xf3 sys/kern/kern_timeout.c:-1 softclock_thread(ffff80002a72cf90) at softclock_thread+0x12b softclock_thread_run sys/kern/kern_timeout.c:842 [inline] softclock_thread(ffff80002a72cf90) at softclock_thread+0x12b sys/kern/kern_timeout.c:866 end trace frame: 0x0, count: -10 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80002a739ab0 rbx 0xffff80000156b800 rdx 0 rcx 0 rax 0xffff80002a72cf90 r8 0x101010101010101 r9 0x8080808080808080 r10 0xbf48e2449a015389 r11 0x64751984cbc6092c r12 0 r13 0xffff80002a72cf94 r14 0 r15 0x1 rip 0xffffffff82215455 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80002a739aa0 ss 0 db_enter+0x25: addq $0x8,%rsp ddb> show proc PROC (softclock) tid=452080 pid=84982 tcnt=1 stat=onproc flags process=14000 proc=40000200 runpri=0, usrpri=50, slppri=0, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff80002a72d228,0xffff80002a72c7d8 process=0xffff8000ffffdb00 user=0xffff80002a734000, vmspace=0xffffffff839ad710 estcpu=0, cpticks=0, pctcpu=0.0, user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 63328 311732 70200 0 2 0 syz-executor 63328 289003 70200 0 3 0x4000080 sbwait syz-executor 77758 353372 66549 0 2 0xc80 syz-executor 77758 159244 66549 0 3 0x4000080 fsleep syz-executor 77758 414884 66549 0 3 0x4000080 kqpoll syz-executor 77758 81042 66549 0 3 0x4000080 fsleep syz-executor 36258 394075 0 0 3 0x14200 acct acct 98332 269705 94519 0 2 0xc80 syz-executor 98332 104528 94519 0 3 0x4000080 sbwait syz-executor 98332 243920 94519 0 3 0x4000080 fsleep syz-executor 96870 496028 81845 60928 2 0xc90 syz-executor 96870 130764 81845 60928 3 0x4000090 ttyin syz-executor 96870 510011 81845 60928 3 0x4000090 fsleep syz-executor 76029 380011 10254 0 2 0xc80 syz-executor 76029 87760 10254 0 3 0x4000080 ttyin syz-executor 76029 6798 10254 0 3 0x4000080 fsleep syz-executor 48994 364787 29062 60929 2 0xc90 syz-executor 48994 272969 29062 60929 3 0x4000090 kqsel syz-executor 48994 462464 29062 60929 3 0x4000090 fsleep syz-executor 97772 289804 1 0 3 0x82 nanoslp getty 29062 489427 50792 0 3 0x82 nanoslp syz-executor 94519 97886 50792 0 3 0x82 nanoslp syz-executor 99287 51858 50792 0 2 0xc82 syz-executor 10254 135104 50792 0 2 0xc82 syz-executor 81845 58888 50792 0 3 0x82 nanoslp syz-executor 66549 483973 50792 0 3 0x82 nanoslp syz-executor 64077 193200 50792 0 2 0xc82 syz-executor 70200 239480 50792 0 3 0x82 nanoslp syz-executor 50792 145095 48525 0 3 0x82 kqread syz-executor 48525 113037 41010 0 3 0x10008a sigsusp ksh 41010 54702 98935 0 3 0x98 kqread sshd-session 98935 226260 75799 0 3 0x92 kqread sshd-session 75799 418567 1 0 3 0x88 kqread sshd 75054 503869 31243 73 3 0x1100090 kqread syslogd 31243 432022 1 0 3 0x100082 sbwait syslogd 68912 521317 1 0 3 0x100080 kqread resolvd 54839 103506 28234 77 3 0x100092 kqread dhcpleased 13724 174132 28234 77 3 0x100092 kqread dhcpleased 28234 14186 1 0 3 0x80 kqread dhcpleased 48732 18657 0 0 3 0x14200 bored smr 55331 19789 0 0 2 0x14200 zerothread 12362 324057 0 0 3 0x14200 aiodoned aiodoned 83114 176056 0 0 3 0x14200 syncer update 44298 58214 0 0 3 0x14200 cleaner cleaner 74252 435870 0 0 3 0x14200 reaper reaper 76515 335912 0 0 3 0x14200 pgdaemon pagedaemon 90412 211599 0 0 3 0x14200 bored viomb 19461 393270 0 0 3 0x40014200 acpi0 acpi0 31348 174105 0 0 3 0x14200 bored softnet0 65786 21470 0 0 3 0x14200 bored systqmp 39318 354682 0 0 3 0x14200 bored systq *84982 452080 0 0 7 0x40014200 softclock 46658 60228 0 0 3 0x40014200 idle0 1 210415 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb> show all locks No such command ddb> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 11059 12181K 12872K 166960K 13063 0 pcb 20 15K 17K 166960K 164 0 rtable 262 9K 10K 166960K 479 0 pf 39 14K 15K 166960K 98 0 ifaddr 46 8K 8K 166960K 87 0 ifgroup 63 2K 2K 166960K 140 0 sysctl 3 1K 9K 166960K 40 0 counters 38 18K 18K 166960K 76 0 ioctlops 0 0K 4K 166960K 145 0 iov 1 4K 16K 166960K 85 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1369 86K 87K 166960K 1794 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 5K 166960K 10 0 VM map 2 1K 1K 166960K 2 0 sem 11 0K 0K 166960K 18 0 dirhash 12 2K 2K 166960K 24 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 18 65K 350K 166960K 576 0 sigio 0 0K 0K 166960K 9 0 proc 60 59K 100K 166960K 524 0 subproc 72 4K 4K 166960K 72 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 58 0 in_multi 92 7K 7K 166960K 127 0 ether_multi 1 0K 0K 166960K 3 0 mrt 0 0K 0K 166960K 1 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 109 493K 493K 166960K 109 0 exec 0 0K 1K 166960K 388 0 fusefs mount 1 32K 32K 166960K 1 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 248 143K 159K 166960K 6724 0 UVM aobj 15 4K 6K 166960K 21 0 pinsyscall 39 78K 96K 166960K 1630 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 1 0K 0K 166960K 159 0 NDP 16 0K 2K 166960K 55 0 temp 47 8664K 8728K 166960K 8995 0 kqueue 14 22K 31K 166960K 109 0 SYN cache 2 16K 16K 166960K 2 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle rtpcb 120 98 0 94 1 0 1 1 0 8 0 rtentry 136 141 0 32 4 0 4 4 0 8 0 unpcb 144 441 0 420 2 0 2 2 0 8 1 syncache 336 5 0 5 1 0 1 1 0 8 1 tcpqe 32 2 0 2 1 0 1 1 0 8 1 tcpcb 736 197 0 192 2 0 2 2 0 8 1 arp 96 20 0 3 1 0 1 1 0 8 0 ipq 40 2 0 0 1 0 1 1 0 8 0 ipqe 40 2 0 0 1 0 1 1 0 8 0 inpcb 328 645 0 634 10 0 10 10 0 8 8 ip6q 72 2 0 0 1 0 1 1 0 8 0 ip6af 40 1 0 0 1 0 1 1 0 8 0 nd6 112 30 0 7 1 0 1 1 0 8 0 pkpcb 40 1 0 1 1 0 1 1 0 8 1 kcovpl 48 8 0 0 1 0 1 1 0 8 0 ppxss 1072 29 0 26 1 0 1 1 0 8 0 pppxif 1416 10 0 9 1 0 1 1 0 8 0 art_heap8 4096 5 0 1 4 0 4 4 0 8 0 art_heap4 256 599 0 128 30 0 30 30 0 8 0 art_table 40 604 0 129 5 0 5 5 0 8 0 art_node 32 139 0 40 1 0 1 1 0 8 0 sysvmsgpl 40 1 0 0 1 0 1 1 0 8 0 semupl 112 2 0 2 1 0 1 1 0 8 1 semapl 112 15 0 6 1 0 1 1 0 8 0 shmpl 112 16 0 5 1 0 1 1 0 8 0 dirhash 1024 25 0 8 3 0 3 3 0 8 0 dino2pl 256 2421 0 918 95 0 95 95 0 8 0 ffsino 256 2421 0 918 95 0 95 95 0 8 0 nchpl 144 3190 0 1491 64 0 64 64 0 8 0 rtmask 32 6 0 6 1 0 1 1 0 8 1 vnodes 216 2734 0 0 152 0 152 152 0 8 0 namei 1024 10179 0 10179 1 0 1 1 0 8 1 vcpupl 3904 1 0 0 1 0 1 1 0 8 0 vmpool 808 2 0 1 1 0 1 1 0 8 0 kstatmem 264 74 0 44 3 0 3 3 0 8 1 scsiplug 72 4 0 4 1 0 1 1 0 8 1 scxspl 216 9829 0 9829 8 0 8 8 1 8 8 plimitpl 152 105 0 88 1 0 1 1 0 8 0 sigapl 424 835 0 791 6 0 6 6 0 8 1 knotepl 120 18664 0 18614 10 0 10 10 0 8 8 kqueuepl 184 164 0 150 1 0 1 1 0 8 0 pipepl 304 147 0 119 3 0 3 3 0 8 0 fdescpl 448 821 0 791 5 0 5 5 0 8 1 filepl 120 4888 0 4651 10 0 10 10 0 8 2 lockfpl 104 141 0 137 1 0 1 1 0 8 0 lockfspl 48 64 0 60 1 0 1 1 0 8 0 sessionpl 144 22 0 15 1 0 1 1 0 8 0 pgrppl 48 32 0 17 1 0 1 1 0 8 0 ucredpl 104 663 0 649 1 0 1 1 0 8 0 zombiepl 144 793 0 791 1 0 1 1 0 8 0 processpl 1152 835 0 791 4 0 4 4 0 8 0 procpl 664 1475 0 1419 6 0 6 6 0 8 1 sosppl 176 5 0 5 1 0 1 1 0 8 1 sockpl 552 1207 0 1171 10 0 10 10 0 8 7 mcl64k 65536 87 0 86 1 0 1 1 0 8 0 mcl8k 8192 43 0 43 1 0 1 1 0 8 1 mcl4k 4096 2992 0 2939 16 1 15 16 0 8 8 mcl2k 2048 887 0 884 2 0 2 2 0 8 1 mtagpl 96 93 0 7 3 0 3 3 0 8 0 mbufpl 256 9907 0 9651 21 0 21 21 0 8 4 bufpl 280 3000 0 120 206 0 206 206 0 8 0 anonpl 24 148789 0 145508 44 0 44 44 0 187 21 amapchunkpl 152 21412 0 20884 35 0 35 35 0 158 13 amappl16 200 2888 0 2855 19 8 11 15 0 8 8 amappl15 192 43 0 43 1 0 1 1 0 8 1 amappl14 184 15 0 15 1 0 1 1 0 8 1 amappl13 176 409 0 408 1 0 1 1 0 8 0 amappl12 168 1168 0 1129 2 0 2 2 0 8 0 amappl11 160 6 0 6 1 0 1 1 0 8 1 amappl10 152 46 0 36 1 0 1 1 0 8 0 amappl9 144 245 0 245 1 0 1 1 0 8 1 amappl8 136 26 0 25 1 0 1 1 0 8 0 amappl7 128 96 0 95 1 0 1 1 0 8 0 amappl6 120 264 0 252 1 0 1 1 0 8 0 amappl5 112 87 0 80 1 0 1 1 0 8 0 amappl4 104 389 0 364 1 0 1 1 0 8 0 amappl3 96 3575 0 3477 3 0 3 3 0 8 0 amappl2 88 940 0 869 2 0 2 2 0 8 0 amappl1 80 10640 0 10106 13 0 13 13 0 8 1 amappl 88 5942 0 5762 5 0 5 5 0 92 0 uvmvnodes 80 111 0 0 3 0 3 3 0 8 0 dma4096 4096 1 0 1 1 0 1 1 0 8 1 dma1024 1024 1 0 0 1 0 1 1 0 8 0 dma256 256 6 0 6 1 0 1 1 0 8 1 dma128 128 255 0 255 1 0 1 1 0 8 1 dma64 64 6 0 6 1 0 1 1 0 8 1 dma32 32 7 0 7 1 0 1 1 0 8 1 dma16 16 18 0 17 1 0 1 1 0 8 0 aobjpl 72 20 0 6 1 0 1 1 0 8 0 uaddrrnd 24 821 0 791 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 821 0 791 1 0 1 1 0 8 0 vmmpekpl 168 8014 0 7984 2 0 2 2 0 8 0 vmmpepl 168 58855 0 57017 90 0 90 90 0 357 9 vmsppl 368 820 0 791 4 0 4 4 0 8 1 rwobjpl 40 18454 0 17475 13 0 13 13 0 8 2 pdppl 4096 1653 0 1585 100 32 68 81 0 8 0 pvpl 32 372964 0 363755 104 0 104 104 0 265 23 pmappl 216 822 0 792 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 385 0 33 11 0 11 11 0 8 0 ddb> machine ddbcpu 0 No such command ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83325ab2) at panic+0x1cf sys/kern/subr_prf.c:198 rw_do_enter_read(ffff80000156b860,0) at rw_do_enter_read+0x435 sys/kern/kern_rwlock.c:379 in6_hasmulti(fffffd8070f5d2f0,ffff80000156b800) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline] in6_hasmulti(fffffd8070f5d2f0,ffff80000156b800) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150 ip6_output(fffffd8070f5d200,ffffffff839adbf8,0,0,ffff80002a739da0,0) at ip6_output+0x1369 sys/netinet6/ip6_output.c:507 mld6_sendpkt(ffff8000015ae080,83,0) at mld6_sendpkt+0x364 sys/netinet6/mld6.c:499 mld6_fasttimo() at mld6_fasttimo+0x16d mld6_checktimer sys/netinet6/mld6.c:395 [inline] mld6_fasttimo() at mld6_fasttimo+0x16d sys/netinet6/mld6.c:369 pffasttimo(ffffffff838bf828) at pffasttimo+0x184 sys/kern/uipc_domain.c:-1 timeout_run(ffffffff837b82a0,ffffffff838bf828) at timeout_run+0xf3 sys/kern/kern_timeout.c:-1 softclock_thread(ffff80002a72cf90) at softclock_thread+0x12b softclock_thread_run sys/kern/kern_timeout.c:842 [inline] softclock_thread(ffff80002a72cf90) at softclock_thread+0x12b sys/kern/kern_timeout.c:866 end trace frame: 0x0, count: -10 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83325ab2) at panic+0x1cf sys/kern/subr_prf.c:198 rw_do_enter_read(ffff80000156b860,0) at rw_do_enter_read+0x435 sys/kern/kern_rwlock.c:379 in6_hasmulti(fffffd8070f5d2f0,ffff80000156b800) at in6_hasmulti+0x41 in6_lookupmulti sys/netinet6/in6.c:-1 [inline] in6_hasmulti(fffffd8070f5d2f0,ffff80000156b800) at in6_hasmulti+0x41 sys/netinet6/in6.c:1150 ip6_output(fffffd8070f5d200,ffffffff839adbf8,0,0,ffff80002a739da0,0) at ip6_output+0x1369 sys/netinet6/ip6_output.c:507 mld6_sendpkt(ffff8000015ae080,83,0) at mld6_sendpkt+0x364 sys/netinet6/mld6.c:499 mld6_fasttimo() at mld6_fasttimo+0x16d mld6_checktimer sys/netinet6/mld6.c:395 [inline] mld6_fasttimo() at mld6_fasttimo+0x16d sys/netinet6/mld6.c:369 pffasttimo(ffffffff838bf828) at pffasttimo+0x184 sys/kern/uipc_domain.c:-1 timeout_run(ffffffff837b82a0,ffffffff838bf828) at timeout_run+0xf3 sys/kern/kern_timeout.c:-1 softclock_thread(ffff80002a72cf90) at softclock_thread+0x12b softclock_thread_run sys/kern/kern_timeout.c:842 [inline] softclock_thread(ffff80002a72cf90) at softclock_thread+0x12b sys/kern/kern_timeout.c:866 end trace frame: 0x0, count: -10